Inspection apparatus



April 1953 H. R. HUGHES 2,635,747

INSPECTION APPARATUS- Filed May 29. 1947 2 SHEETSS HEET 1 INVEN TOR.

HARLEY RoLA/vo flue/15.5

Patented Apr. 21, 1953 UNITED STATES PATENT OFFICE INSPECTION APPARATUS Harley Roland Hughes, Louisville, Ky., assignor to Colgate-Pahnolive-Peet Company, Jersey City, N. J., a corporation of Delaware Application May 29, 1947, Serial N 0. 751,496

3 Claims.

This is an improvement over the apparatus of the copending application of myself and Curtis D. Rice Serial No. 601,530 filed June 25, 1945, now Patent No. 2,529,081 wherein is disclosed a photo-- electric inspection apparatus in which the moving container engages a light shuttercontrol lever as it enters the inspection station to render the inspection and rejection device responsive solely to the scanned substance level in the container while the latter is in the inspection station. I have found that this trip lever arrangement is satisfactory where the filled containers are fairly heavy, but Where the packaged substance is relatively light, as certain detergent powders, difficulty is encountered in that the moving container may not be substantial enough to push the trip lever aside and thus may fail to activate the inspection apparatus. I

The present invention overcomes this difiiculty in that it substitutes an additional photoelectric control for the mechanically operated trip lever of the application, whereby the inspection operation is made independent of the container weight and makes certain refinements in the apparatus as will be described below.

It is therefore the major objectof my invention to provide a novel apparatus for determining the level of a substance in a moving container wherein'photoelectric means controlled by movement of a container into the inspection station activates associated photoelectric means adapted to scan the substance level and eject the container if it is improperly filled! Either the container or the substance, or both, .may be opaque.

Further objects of the invention willoappear as the description proceeds in connection with the appended claimsand the annexed drawings wherein:

Figure 1' is a side elevation of an inspection apparatus according to a preferred embodiment of the invention;

inspecting and/ or 7 Figure 2 is a top plan view of the apparatus of Figure 1 illustrating the container controlled photoelectric system;

Figure 3 is an end view mainly insection of the apparatus of Figures 1 and 2;

Figure 4 is a schematic and wiring diagram of the apparatus; I

Figure 5 is a diagrammatic view of a further type of container ejectorvwhere an improperly filled container is transferred to another conveyor; and

Figure 6 is a diagrammatic plan view corresponding to Figure 5.

Figure l in the preferred embodiment illustrates. an inspection station on a conveyor line between an automatic filling machine and a suitable container closing device. A flat conveyor I I, preferably of the endless belt type, carries a succession of filled containers l2through the inspection station with their top flaps open to permit scanning of the substancelevel. k

A frame 13 arises at one side of the conveyor support It and has a horizontal upper shelf l5 projecting over the conveyor at a height sufiicient to clear the moving containers. Plates I6 and liv at opposite ends of shelf I5 are slidably adjustable toward and away from each other parallel to the conveyor in suitable guides I8 and I8, bolt and slot assemblies 20 and 2| in the plates and shelf providing for locking the plates in adjusted position. p

Upstanding from plate I6 is a lug on which a flexible clamp 22 is adjustably pivoted at 23. A similar flexible clamp 24 is adjustably pivoted at 25- on plate l1. Clamps 22' and '24 support respectively a housing 26 for a photoelectric cell and a housing 2'! for a light source, light being used in thesense of radiation of any suitable wavelength which will activate the photocell. Housing 26 is provided with a cylindrical front bafiie 28, and housing 21 is provided with a simi--' lar baiile 29 whereby the light emitted from housing 21 is confined to the beam indicated at 3!, andjthe baffle 28 substantially prevents entry into housing 26 of light other than along the reflected beam path indicatedat 32.

Housings 26 and 21 are centered transversely of the conveyor and are preferably so arranged that beam 3| intersects the substance level at about 45 to the horizontal and the reflected light path 32 is also about 45. In Figure 1 a properly filled container I2 is illustrated as it passes through the inspection station, with the light from beam 3! reflected from the average acceptable substance level 'M into "the photocell 3 housing 26. The adjustments at 20, 2| and 23, permit the apparatus to be used with containers of different length along the conveyor and difierent substance levels. As illustrated, should the substance level be too high, as at H, or too low as at L, the light beam 3! will not be reflected into housing 26, but any substance level between these limits will reflect some light into housing 25. Since the response of the photoelectric cell at 26 is proportional in magnitude to the strength of the entering light, by suitable cir-, cuit adjustments I can narrow the permissible range of substance levels. The same result can be obtained by suitable baflies.

Where the container I2 :is a rectangular box, as in the preferred embodiment, I provide sta: tionary parallel guides 33 at the inspection sta-r tion for centering the containers, and at the level of the top of the box I provide en frame I3 a stationary fiat guide shoe 34 parallel to the conveyor and having a curved front iace 35 to aid in centering the containeron-the conveyor. M Ahorizorital frame member 36 carries an out,- wardly extending support arm 31 on which a clamp 38 for a photoelectric cell housing 39 is adjustably pivoted on .a horizontal axis at fl'L' Prefera'bly housing 39 is located generally centrally of the inspection station as illustrated in'Figure l and with the axis of its cylindrical iront baffle 42' horizontal and normal to the cone veyor direction. Cylindrical front baflie 42 on housing 39 restricts the field of the photocell. On" the other side of the conveyor from photo: te u i ati nar support 43 estea pa le t th tn tru rt 43 is f rmat with slots 44 .and 45 in which lamp hous ng ha e 1 m" are' lit t i i ,i$t@ W l anti ar o each Qtt r Patt 219 5 8 4 and ,49; secured to their bases by clamps 59 lilge that'at .34, are provided with cylindrical frgnt Bates 51' a d h to v strtl d rec ht i zontal pilot light beams 53 and 54 at equal angles across the conveyor at the inspection 1 station "to intersect within photoce l housing 39. 'l-lousings 3 9 8.and 49 are at the same horizcntal level.

T e s t n and t t tnt t lamp h n s a 419 are isuth t a te aiter m n through the inspectiori' station will cutofi the light'pass defined by both beams t3 and 54 at thesame time f r ap cd termin p iod w ic is a function of the dirnen sionioif the .qqlf tainer a s t e nv n e lia e t ttt f t e a rts 9 h sting? 9 and ar u e i h' ai ara tt with 'd fit eat eontainer sizes.

A co ainer e e t n membe i i iztntell niv-Q t lamc at 5 and h ect bf t eontainer engaging bar 51' normally held out or the path of the container by a weight 58 .h ln J e n of a l an txt titn 5. of ejector 55. Weight 58 1s piYQtallyconnected by a link 61 to the armature fiZ of a solenoid 3 mounted on .a bracket 64 rigid with frame it. When solenoid 63 is deenergized, weight 58 holds the parts in the positions illustrated in Figure 3. When solenoid 63 is energized, armature 52 is .pulled up and acts through link 6l to rock ist t 5 t kw se in F u e 3 to. tran ers y move bar 5] over the top oi the conveyor and tatsft a c a r it th t a be in it stth to be dumped laterally off the conveyor,

liigure 4 illustrates the general circuit arrange: m i Th u a .1 ol npu n t mina at :64 includes a switch 65 and is connected to th Pr m r or a ra ftrmt 69 havin a 5:8

'lamp housings 26, 48 and 49.

4 volt secondary connected to the lamps within These lamps are energized when switch 65 is closed. The input line also supplies energy to a suitable relay device 66 that contains a suitable control circuit for amplifying the photocell current and controlling the energization of output terminal 61. The photoelectric cells in housings -21 and 33 which are preferably of the gas discharge type are connected in parallel and to the common circuit within relay 66. When switch 65 is open the whele system of Figure 4 is deenergized and the'parts are maintained as in Figure 3. The relay circuit characteristics are such that when either .cr bethof'thephotoelectric cells are energized by incidentlight from the lamp housings so as tc provide a predetermined current flow in their common circuit, the output terminal 67 isniaintained deenergized and the ejector maintains the positionof Figure 3. This cond nmrt ai wh i it' i I Q tfi ll M1911 Withinithe' in e ion' ta ioa .9 n he s nc v l n a tqt tier' a th i em statigi} is Within permissible limits. The ill m1- nation level of the lamps" at 26, 48 and 519 "is 11 1 h er ha t e srmal ro li h level, ltn ts n refe ab sed to 1it tt t e b m t ha th e is n c n U l switth 55 is closed. h n t 6 i ose t ener ize the tam. an th l t beam c th o e ect ic te r mtl tn i t cf as when, .9 1? tame tilt Off 29 h b ams an 5.4 int' inspection station and the substance levelin the tt taiect e e t twtii tt hi h t6 ftfl l team .iP'PQWH ne n thcp ttt r tria l d u rent fle the c r tit ta 'l'sl t t a rcdt t m nt i exten are .ti ts'e tth' t ith ke (ac sh wn to ener ize te mina a th re or acti e sc a 'd it caus .e'ietr 55 t d m t e aitrqtt l fi l d ttni a i ti" frtrfi he .tQttr at s te the "tont i i damned th i h ea s 53' a it a b ttkt an he leno d i t i iz t t m he ca t r t rn to th qtit o j 'u 'tf- Du in t tien ith'tWl th t5 titte a seri o n ta pe s a e c nta n r a moved through the inspectien sem n: Fori a b ie in a a illustra in F u 1i tertaie 1.5 i es ed a i sptt t t atwe and ti t? 9. T l ght eam .53 as 5 sma te ously, so that during that interval anteater t? is ta er th stl j t ttr tith steam le l talinis light an t jqt lt ltt b n t tn are an m mptrly fine tt ai e l b 'fi mtq aei ttmetme the en N0 attt htt e' made t testribe the spe fic t li it tt'd t rt tirtitdetaii within relay 66, it being understood that such may tempest a titt letir t ata ac solenoid 63 when light is cut 01? to both photo.- cells and deenergizes'solenoid 63 whenever light is received by either photocell. In practiced have used at 55 the relay device made by en l ltt t C m a esi at a t i Photoelectric Relay CR'7505A100f I lvly improved device accurately detects and immediately ejects improperly filled containers. As each container enters the station itin te r cepts light beam 53, but is not subjected to control of the level scanning devicetuntil it advanced Wholly Within the station and cuts off both beams 53 and 54. As soon as the trailing end of the container passes beam 53, the ejector is immediately rendered inoperative.

Sometimes the upstanding open flap at the leading end of the container when part way through the inspection station will temporarily cut oil beam 3|, but at that time beam 54 is still unblocked and prevents energization of the ejector. By the time that the container reaches the position where it intercepts both beams 53 and 54, the leading flap has unblocked beam 3| and the surface of the substance is exposed for scanning. Thus my improved device makes the inspection operation independent of the container mass and independent of accidental out off by the upper flaps of the container.

Instead of dumping improperly filled containers off the conveyor I I, I may merely transfer them onto another conveyor running side by side with conveyor I l but in the opposite direction and leading away from the inspection station, to prevent spilling the rejected container contents. As illustrated in Figures 5 and 6 this may be accomplished by a horizontally reciprocating pusher ii, suitably operated through a single revolution clutch I2 driven by a separate electric motor 13 or by a power take oiT in the apparatus. Such a clutch could be of the construction disclosed in United States Letters Patent No. 2,283,962 with a trip control lever 14 connected to the armature of a solenoid 75 under control of the above described photoelectric devices. For example this solenoid 15 may be the earlier described solenoid 63 connected to the clutch trip mechanism for operating pusher H through a single stroke cycle whenever an improperly filled container is detected at the inspection station. The output shaft 76 of clutch 12 carries an eccentric l! for rocking a lever 18 pivoted at 19 and connected by a pin and slot to the reciprocable pusher ll. Lever i8 is biased in one direction by spring 8! so that pusher H is normally maintained in the full line position of Figure 5.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than loy the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United. States Letters Patent is:

1. In apparatus for checking the filling of containers, a conveyor for moving open-topped containers each having an upstanding closure flap at its leading end in succession through an inspection station, a photoelectric inspection device at said station comprising means for projecting a beam of light downwardly onto the surface of the substance within the container at the inspection station and light sensitive means for receiving light reflected from said surface within a predetermined angular zone, means operated by said device for ejecting improperly filled containers from said conveyor, means on one side of the conveyor for projecting a light pass substantially equal to but slightly less than the Width of the container taken in the direction of movement of the conveyor and further light sensitive means in the path of said light pass, said light pass extending a I predetermined horizontal distance above the conveyor so that while passing through said station each container will block said light pass for a predetermined period when said container is positioned wholly within said station with its leading closure flap clear of said inspection light, and means connecting said further light sensitive means to permit actuation of said container ejecting means by said first light sensitive means only when said container wholly blocks said light pass.

2. In photo-electric apparatus for inspecting a moving succession of filled open topped containers and for rejecting improperly filled containers, an inspection station, a conveyor for moving said succession of containers through said station, a photoelectric scanning device above the containers at said station for measuring the substance level in each container, means for controlling actuation of said scanning device comprising means for projecting two horizontally spaced light beams across said conveyor at said station and light sensitive means for receiving said beams after traversal of the conveyor, said light beams defining light passes having a predetermined effective width above the conveyor in the path of movement of the container which is slightly less than the dimension of the container in that direction, a container ejection device at said station, and means operable only during the period that the container disposed at said station intercepts both said light beams for rendering said ejection device controllable by said scanning device.

3. Apparatus for checking the level of a substance in a succession of containers which comprises in combination means defining an inspection station containing light sensitive means which includes two separate but operably associated photoelectric cell units, a conveyor for transporting a succession of filled containers each having an upstanding closure flap on its leading end to said station, container handling means operably associated with said light sensitive means and adapted to remove improperly filled containers from said conveyor, means for directing a beam of light onto the substance in a filled container located at said station wherefrom it is reflected toward one of said photoelectric cell units, means directing a pilot light pass substantially equal to but slightly less than the width of the container taken in the direction of movement of and a predetermined distance above the conveyor onto said second photoelectric cell unit at said station, said pilot light being wholly intercepted upon predetermined positioning of a container within said station whereby said light sensitive means is exposed only to light reflected from said substance.

during only a limited interval while a container is at said station and said leading closure flap has cleared said inspection light beam.

HARLEY ROLAND HUGHES.

References Cited in'the file of this patent UNITED STATES PATENTS Number Name Date 2,142,920 Rose Jan. 3, 1939 2,280,948 Gulliksen Apr. 28, 1942 2,395,482 Hurley Feb. 26, 1946 2,529,081- Hughes Nov. 7, 1950 FOREIGN PATENTS Number Country Date 405,243 Great Britain Apr. 28, 1932 

